Indulging Patrician

• WOTC Official Reminder Textofficial rules
  Lifelink — Damage dealt by this creature also causes you to gain that much life.

• WWizards of the Coast2020-06-23
  Official Ruling
  Indulging Patrician's last ability looks at how much life you've gained in the turn, even if it wasn't on the battlefield when you gained life. It doesn't care if you also lost life, even if you lost more life than you gained.
• WWizards of the Coast2020-06-23
  Official Ruling
  Each opponent loses just 3 life, no matter how much life you've gained past 3 life.
• WWizards of the Coast2020-06-23
  Official Ruling
  If you haven't gained 3 life by the time your end step begins, Indulging Patrician's last ability won't trigger at all.
• WWizards of the Coast2020-06-23
  Official Ruling
  In a Two-Headed Giant game, Indulging Patrician's last ability causes the opposing team to lose 6 life.

Rulings via Scryfall